package com.wl.filter;

import com.alibaba.fastjson.JSON;
import com.wl.common.BaseContext;
import com.wl.common.R;
import com.wl.entity.Employee;
import io.swagger.v3.oas.annotations.parameters.RequestBody;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @创建人 万磊
 * @创建时间 2022/8/7
 * 好好学习，天天向上
 * <p>
 * 过滤器，检查用户是否已经完成登录
 */
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/backend/*")
@Component  //过滤器
@Slf4j
public class LoginCheckFilter implements Filter {

    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;


        //获取本次请求的URL
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}",requestURI);

        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "backend/**",
                "front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };
        //判断本次请求是否需要处理
        boolean check = check(urls, requestURI);
        //如果不需要处理，则直接放行
        if (check) {
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request, response);
            return;
        }
        //判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employee") != null) {
            log.info("用户已登录，用户id为{}",request.getSession().getAttribute("employee"));
            filterChain.doFilter(request, response);

            //公共字段自动填充获取id
            Long empId = (Long)request.getSession().getAttribute("employee");
            BaseContext.getCurrentId(empId);

            return;
        }
        log.info("用户未登录");
        //如果未登录，则返回未登录结果（通过输出流的方式向客户端页面响应数据）
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 进行路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
